{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T11:19:08Z","timestamp":1788434348729,"version":"build-2803163510"},"reference-count":39,"publisher":"American Chemical Society (ACS)","issue":"34","license":[{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/501100018537","name":"National Science and Technology Major Project","doi-asserted-by":"publisher","award":["2025ZD0803500"],"award-info":[{"award-number":["2025ZD0803500"]}],"id":[{"id":"10.13039\/501100018537","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Cross-linking density is a critical parameter governing the performance of cross-linked polymers. Rapid and accurate determination of this parameter is essential for evaluating material states, assessing engineering applicability, and optimizing processing conditions. However, conventional methods suffer from drawbacks such as operational complexity, sample destructiveness, and high instrumentation costs. Herein, we propose a novel fluorescence-based visualization strategy that employs aggregation-induced emission (AIE) molecules as fluorescent probes for the rapid and quantitative visual detection of polymer cross-linking density. As the cross-linking density increases, the polymer forms a more constrained three-dimensional network, which restricts the intramolecular motion of the AIE probes and consequently enhances their fluorescence emission. Using cross-linked polyethylene (XLPE) as a model material, fluorescence images were captured above the melting temperature using a home-built hot-stage imaging apparatus, and gray values were extracted for quantitative analysis. The fluorescence intensity ratio exhibited a strong linear correlation with cross-linking density (R2 = 0.996), and the method achieved high accuracy with relative errors below 1.64% when benchmarked against nuclear magnetic resonance (NMR) results. Notably, the addition of 0.1 wt % AIE probes had negligible effects on the thermal, mechanical, electrical breakdown strength, and crystallization properties of XLPE. The general applicability of this strategy was further validated in vulcanized cis-1,3-butadiene rubber (V-BR), where excellent linearity (R2 = 0.990) and relative errors below 1.1% were obtained. This work establishes a simple, rapid, and high-precision visualization approach for characterizing polymer cross-linking density, offering a promising tool for real-time monitoring in industrial polymer processing and quality control.<\/jats:p>","DOI":"10.1021\/acs.analchem.6c04654","type":"journal-article","created":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T19:01:30Z","timestamp":1787252490000},"page":"25433-25441","source":"Crossref","is-referenced-by-count":0,"title":["Visualizing\nPolymer Cross-linking Density: A Universal\nFluorescence Strategy Based on Aggregation-Induced Emission"],"prefix":"10.1021","volume":"98","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-2708-1829","authenticated-orcid":true,"given":"Mingce","family":"Tian","sequence":"first","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaiqiang","family":"Luo","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaiyue","family":"Sun","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Wang","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daolei","family":"Lin","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Long","family":"Liu","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanhe","family":"Wu","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiying","family":"Dai","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongjie","family":"Zhang","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Yang","sequence":"additional","affiliation":[{"name":"Beijing Huairou Laboratory , ,","place":["Beijing, China, 101400"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,20]]},"reference":[{"issue":"43","key":"2026090306474832600_cit1","doi-asserted-by":"publisher","first-page":"2507313","DOI":"10.1002\/adfm.202507313","article-title":"Covalent Adaptable Networks with\nAssociative Siloxane Exchange Enabled by Amide-Based Internal Catalysis:\nDesigning for Reprocessability and Extrudability by Increasing the\nCross-Link Density","volume":"35","author":"Purwanto","year":"2025","journal-title":"Adv. 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Actuators,\nB"},{"issue":"83","key":"2026090306474832600_cit26","doi-asserted-by":"publisher","first-page":"12423","DOI":"10.1039\/D3CC03677D","article-title":"Reversible\nfluorescent adhesives based on covalent adaptable networks with dynamic\nAIE crosslinking: in situ visualization of adhesion capability","volume":"59","author":"Jiang","year":"2023","journal-title":"Chem. 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Technol."},{"issue":"7","key":"2026090306474832600_cit29","doi-asserted-by":"publisher","first-page":"1011","DOI":"10.1021\/acsmacrolett.5c00267","article-title":"Impact\nof Cross-Link Density on Polybutadiene\nPermanent and Vitrimer Networks","volume":"14","author":"Ezzeddine","year":"2025","journal-title":"ACS Macro Lett."},{"issue":"1","key":"2026090306474832600_cit30","doi-asserted-by":"publisher","first-page":"112","DOI":"10.1021\/acsanm.4c04855","article-title":"Application of a Hessian-Based\nImage-Processing Method\nfor Enhanced Visualization of Nanoscale Rubber Cross-Linked Network\nStructures from Electron Microscopy Images","volume":"8","author":"Suzuki","year":"2025","journal-title":"ACS Appl. Nano Mater."},{"issue":"7","key":"2026090306474832600_cit31","doi-asserted-by":"publisher","first-page":"3242","DOI":"10.1021\/acs.macromol.4c00038","article-title":"Self-Consistent Theory for Structural\nRelaxation, Dynamic Bond Exchange Times, and the Glass Transition\nin Polymeric Vitrimers","volume":"57","author":"Mei","year":"2024","journal-title":"Macromolecules"},{"issue":"7","key":"2026090306474832600_cit32","doi-asserted-by":"publisher","first-page":"1675","DOI":"10.3390\/ma18071675","article-title":"Molecular Simulation Study on the\nImpact of a Cross-Linked Network\nStructure on the Tensile Mechanical Properties of PBT Substrates","volume":"18","author":"Huang","year":"2025","journal-title":"Materials"},{"key":"2026090306474832600_cit33","doi-asserted-by":"publisher","first-page":"122170","DOI":"10.1016\/j.polymer.2020.122170","article-title":"Modeling water diffusion\nin polybenzimidazole\nmembranes using partial immobilization and free volume theory","volume":"189","author":"Moon","year":"2020","journal-title":"Polymer"},{"issue":"11","key":"2026090306474832600_cit34","doi-asserted-by":"publisher","first-page":"4823","DOI":"10.1021\/acs.biomac.1c01106","article-title":"Effects of Nonhydroxyl\nOxygen Heteroatoms in Diethylene Glycols on\nthe Properties of 2,5-Furandicarboxylic Acid-Based Polyesters","volume":"22","author":"Tian","year":"2021","journal-title":"Biomacromolecules"},{"issue":"18","key":"2026090306474832600_cit35","doi-asserted-by":"publisher","first-page":"1740","DOI":"10.1039\/b105159h","article-title":"Aggregation-induced\nemission of 1-methyl-1,2,3,4,5-pentaphenylsilole","author":"Luo","year":"2001","journal-title":"Chem. 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